Kiln for rapid firing single layers of ceramic articles



CERAMIC ARTICLES Se t. 20, 1966 R. L. BYINGTON KILN FOR RAPID FIRING SINGLE LAYERS OF 2 Sheets-Sheet 1 Filed May 4, 1965 o m 2; HM L 3 '\:r x 'x o m m III M CO TJ S F H4H a I, oo T i r co F" FIHIE) I i: m

m l I zJ- L w LA 8 U 7 a w J E m os 333. comm NNN cu l I 5 m (D a m" 3L 5 9? r 9 1 1 l I J O m u q- 92? m INVENTOR. RALPH L, BYINGTON ATTORNEYS Se t. 20, 1966 R. L. BYINGTON 3,273,218

KILN FOR RAPID FIRING SINGLE LAYERS OF CERAMIC ARTICLES Filed May 4, 1965 2 Sheets-Sheet 2 INVENTOR, RALPH L. BY! N GTON United States Patent 3,273,218 KILN FOR RAPID FIRING SINGLE LAYERS OF CERAMIC ARTICLES Ralph L. Byington, San Jose, Calif., assignor to Armrock Products, Inc., a corporation of California Filed May 4, 1965, Ser. No. 453,121 7 Claims. (Cl. 25-142) The present invention relates to kilns for the rapid firing of ceramic articles such as glazed tile, for example, by applying heat directly to the top and bottom surfaces of such articles, and is concerned more particularly with a kiln in which the expansion of the fire brick construction inherent in such a kiln will not interfere with the operation of the conveying means and provide for the progression of a single layer of the articles to be fired from heat applied both above and below through the oven, the articles being fired, being the only elements progressing through the oven.

More specifically the invention relates to kilns of the above character in which a series of suitable rollers, such as ceramic rollers, are mounted to carry ceramic articles through the oven or firing portion of the kiln, and which rollers are mounted and journaled in such a way so as to be free to rotate at all times and not to be jammed or interfered with by the expansion of the fire brick portion of the kiln when heated.

It is an object of the invention, therefore, to provide a kiln for the fast firing of ceramics, such as glazed tile, in which the fire brick portion of the kiln is divided into two parts separated by metal support and expansion structure and which provides a compact oven portion through which permanently journaled rollers extend and are driven so as to convey the article to be fired in the kiln directly over these rollers through the oven.

A further object of the invention is to provide a kiln wherein a roller journaling structure between an upper fire brick portion and lower fire brick portion is so constructed as to compensate and allow for expansion and contraction during the heating and cooling of the fire brick and the entire kiln without interfering with ope-ration of the rollers during the progression of the objects being fired thereover.

Still another object of the invention is to provide a kiln of the character referred to above in which the metal interponent structure between the upper and lower fire brick portions of the oven is connected to or supported by a fibrous insulating material of resilient character such as ceramic or clay fiber so that relative movement is permitted between the metallic interponent structure and the fire brick portions.

It is still a further object of the invention to provide a kiln of the above character wherein the firing oven is divided into two portions for use with articles such as ceramic tile, the first portion having a higher heat unit input to bring the tile up to the required temperature for firing of the body portion and melting and degassing of the glaze applied to the tile and the subsequent portion of the firing oven is provided with suflicient heat to maintain the required temperature which effects soaking and maturing of glaze on the tile.

The above and other objects of the invention are obtained as described in connection with a preferred embodiment of the invention in which:

FIG. 1 is a top plan view of the kiln with certain parts broken away to illustrate the conveying rollers.

FIG. 2 is a side elevation of the entire kiln shown on a reduced scale.

FIG. 3 is an enlarged end view as seen from the right of FIG. 2, with certain parts shown in section to illustrate details of construction.

3,273,218 Patented Sept. 20, 1966 FIG. 4 is an enlarged fragmentary portion of FIG. 2 illustrating the drive arrangement for the rollers in the firing oven through which the material progresses.

FIG. 5 is an enlarged transverse sectional view through the oven, taken as indicated by the line 5-5 in FIG. 1 and illustrating the details of the metal interponent structure for supporting the upper fire brick portion and the journaling means for the rollers.

FIG. 6 is a side elevational view of the portion shown in FIG. 5 on the same enlarged scale and illustrates the position of certain expansion joints in the metal and also V the journaling of the rollers.

Referring first to FIGS. 1 through 4, the kiln of the present invention includes a frame indicated generally at 10 having upright legs or side posts 11 spaced therealong formed of channel or angle as may be suitable, and arranged in opposite pairs along the length of the kiln. Each of the pairs of posts 11 is connected at the bottom by cross piece 12 (FIG. 3). Adjacent the top of each pair of opposite legs 11 there is provided, in each instance, a cross angle 13 (FIGS. 3 and 4) which extends beyond both of the legs 11 to support the bottom end of a vertical plate or frame member 14, which supports at its top the bottom horizontal flange of a side frame channel 16, which may be welded thereto. The entire side channel structure is composed of several channels 16 as seen, for example, in FIG. 6 where a gap 16a is provided between the adjacent ends of two of these side channels 16 to allow for expansion due to heating from the firing oven. The dotted lines indicate the approximate extent of expansion of the end surfaces of the two adjacent angles 15, as seen in FIG. 6. The angles 15 at the left of FIG. 5 are mounted in the same manner as the channels 16. The side frame angles 15 and channels 16 provide journaling for the ceramic rollers as referred to hereinafter.

The vertical plates 14 (FIG. 6) have the plane of their major dimension lying perpendicular to the length of the kiln so as to be free to flex laterally between their different points of connection or welding to the frame structure of the metal portion of the kiln in response to changes in temperature. Referring to FIGS. 3 and 5, it will be seen that each of the frame members 14 at the right of these views has Welded to the top thereof one of series of channels 16. The upper part of each vertical plate 14 (FIGS. 5 and 6) is also connected by butt welding to U-shaped flexible steel plate or strip 21 which extends inwardly at the top and has its upper end butt welded to one of a plurality of side angles 22 which preferably are formed of a rust-resistant material, such as stainless steel, and have their adjacent ends spaced apart as seen in FIG. 6 at 22a to provide an expansion joint. The opposite series of angles 22 are similar. Each of the angles 22 has the upper edge of its vertical flange welded to a corresponding longitudinally extending side angle 23 whose horizontal flange rest on the horizontal upper portions of the U-shaped flexible steel plates 21. Erected vertically from each of the U-shaped pieces 21 is a vertical plate 26 and each opposed pair of vertical members are connected by a cross angle or piece 27 to complete the framing. Referring to FIG. 5 it Will be readily seen that the U-shaped side frame plate 21 provides for relative vertical expansion between portions of the side frame structure which is formed of a suitable material, such as steel, and will accommodate also any expansion. of the fire brick associated therewith as will subsequently be described.

' Associated with the metal framework or interponent structure described, there is provided both an upper kiln part or portion of fire brick, and lower kiln part or portion of tire brick provided with respective supports on the metal frame as hereinafter described. An entrance or preheating kiln portion 30 is provided without burners Where the article is subjected to gas flowing from the heated portion of the kiln to assist in drying out and bringing the article up to temperature. The structure of this portion of the kiln is substantially the same as that about to be described except for omission of the burners. The lower portion of the fire brick of the kiln includes respective fire bricks 31 which are laid loosely in two horizontal layers on a suitable support such as a plate 32 carried by the cross angles 13 provide expansion spaces between adjacent brick of a layer. At the ends of the horizontal fire brick 31 there are provided two vertical rows of the fire bricks 33 to form the side of the lower fire brick portion of the kiln. This lower part includes the heating part of the oven including a fire space or combustion chamber 34, referred to hereinafter which is defined at the top by silicon carbide plates 36 supported, in each case by a pair of vertically disposed fire bricks 37. The edges of the silicon carbide being spaced from each other and from the side bricks 33 so as to provide entrances for the flames from the respective sets of burners 41 and 42 on either side, these burners also being referred to hereinafter.

Above the silicon carbide plates 36 (FIGS. 3 and there is an open space extending through the length of the kiln and forming the actual firing oven. The top of this firing oven 46 is defined by a series of long horizontal fire bricks 47 which extend between and are supported on the horizontal flanges 22a by a resilient layer 48 of fiber insulation, preferably formed of ceramic or clay fibers. The end edges of the lower fire brick 47 are also separated by similar ceramic fiber insulation 48 from the vertical portions of the angle 22 and the angle 23. It will be noted that the ceramic insulation material 48 extends beyond and across the lower flange of the angles 22 and completely protects the edge of these angles from the heat of the oven. Above the horizontal fire brick 47 there are provided an appropriate number of layers of fire brick 49 to complete the upper part of the oven.

In connection with this oven it is to be noted that the silicon carbide plates 36 are spaced from each other and from the adjacent side walls 33 of the fire bricks so that the flame from the burners may partially pass into the oven and the heat can pass freely into the oven by circulation as well as being supplied also by radiation. If desired, the plates 36 may be perforated to provide an entrance for heat and flame to the firing oven from the firing part of the kiln disposed below the silicon carbide plates. It will be noted that the resiliency of the fibrous layer 49 between the bricks 47 and the angles 22 and 23 allow for lateral expansion in response to expansion of the fire brick 47. Disposed below the angle 22 is another layer of fibrous insulating material or clay wool 51, which may be integral with the clay fiber mass 48 and which is interposed between the lower flange of the angle 22 and a longitudinal series of fire brick 52 which are drilled and supported by bolts 53 from the flanges of the angles 22 at each side. This fibrous insulating material continues around the outside of the fire bricks 52 and into the oven 46 and rests on the top of the lower fire bricks 33. This fibrous insulating material is pierced to provide openings for the rollers 56, such as hollow ceramic rollers, which extend therethrough and are journalled in enlarged holes 55 in the angles 15 and the channels 16. The enlargement of or shifting of the ceramic rollers under heat, and the insulating fiber material 54 interposed between the point of journaling in the channel 16 and the oven itself decreases the amount of expansion of a roller in the journal means therefor.

In order to drive the ceramic rollers 56, each of them is provided at its left end as viewed in FIG. 5 with a pinion 61, which meshes at its top edge with a chain 62 held in place thereon by a longitudinal series of retaining plates 63. Each strap or plate 63 has welded thereto a pair of studs or bolts 64 which pass through a support plate 65 to secure retaining nuts 66 both above and below the plate 65 welded to the adjacent side plate 21. The plate 65 adjustably supports the adjacent retaining plate 63, The lower stretch of the chain 62 rests on and travels along the horizontal flange of the angle 15.

Referring to FIG. 6, it will be seen that at intervals there are gaps 71 between the adjacent angle portions 22 and 23 so as to allow for longitudinal expansion thereof, and, in this connection, the dotted line representation in FIG. 6 of the vertical straps 29, 27, etc., can move in either direction in response to increase of temperature. The U- shaped portions 21 permit up and down movement of the interponent metallic structure between the upper ceramic and the lower ceramic portion of the oven as indicated by the dotted lines in FIG. 5.

Thus structure provides a kiln for handling a single layer of material passing over power driven rollers in a long oven structure in which the metal interponent is flexibly connected and slidably connected to the upper sets of ceramic brick and the lower sets of ceramic brick forming the two fire brick portions of the oven. Thus relative movement between these fire brick portions and the metal interponents can occur, and expansion and contraction of the metal interponents themselves can be taken care of by appropriate bending and moving of the metal and the gaps in the metallic parts as seen in FIG. 6.

Referring again to FIGS. 1 and 2, there is provided at either side of the kiln a gas supply pipe 81 and 82, one of which supplies a set of burners 41 extending inwardly through oven size holes 83 into the combustion chamber of the oven from one side, and the other supplying burners 42 from the other side. Each of these first five pair of burners on the two sides have a single inlet pipe 84 whose inlet valve (not shown) is controlled from a control panel 86 having suitable volumetric and temperature responsive control elements thereon. So that the desired amount of gas is allowed to flow from an end of pipe 86 to the ten burners 83 and 84. Preferably these burners have control valves 91 as seen in FIGS. 3 and 4, and these valves are provided with control handles 92 by means of which they may be individually adjusted in permanent fashion whereas the total amount of flow of these initial burners is controlled from the panel 86. Preferably, these burners are controlled to provide the greatest amount of gas at the first burners 83 and 84 and a decreasing amount along the kiln as the material progresses therethrough and past the vent 93 through which the gas is expelled from the glazing material. Additional vents 93 may be provided along the kiln as required for exhaust of combustion gases and to insure the desired flow of the flame from the combustion chamber through the firing oven. Where electric heaters are used fewer vents will be required.

Also a second set of burners indicated at 101 and 102 are provided along the glaze soaking and setting part of the kiln where a constant temperature is desirably maintained through a second control panel at 103 similar to the control panel 86. And finally the finished tile is discharged onto a cooling section 104 of the roller conveyor.

The spacing apart of the tile conveying rollers is preferably controlled with respect to the smallest dimension of the tile to travel along these rollers so that the tile or other article is always supported by at least two rollers. At the time of transfer of a tile off of a roller, the tile will already be engaged with the third roller. This insures maintaining the planar condition of the article. The exposure of the tile or other ceramic article simultaneously to heat from above or below insures an even penetration of the heat simultaneously from both sides and avoids warping.

While I have shown and described a preferred embodiment of the invention it is apparent that the invention is capable of variation and modification from the form shown so that the scope thereof should be limited only by the scope of the claims appended hereto.

What I claim is:

1. In a kiln for rapid firing of a single layer of ceramic articles such as glazed ceramic tile, an elongated firing oven comprising an upper fire brick construction and a lower fire brick construction, means separating said upper and lower fire brick constructions including a pair of journaling structures extending along each side of said oven, said structures being formed of a material having a dilferent heat expansion characteristic than fire brick, heat insulating means for protecting each of said journalling structures from the heat of the oven, a series of journal means in each of said journaling structures, a series of parallel horizontal rollers journaled in said journal means of said structures, and extending through said oven and said insulating means, said rollers being in an intermediate position in said oven to provide a portion of said oven above said rollers and a portion of said oven below said rollers for direct heating of a ceramic article supported on the rollers and conveyed thereby through the oven, and means for driving said rollers to convey the ceramic articles through the oven.

2. In a kiln as recited in claim 1, in which said structures are metallic in character and have resilient fiber material interposed between the metal of said structures and said fire brick, and in which said heat insulating means consists, at least in part, of ceramic fiber disposed between and surrounding said rollers and in which said series of parallel rollers are formed of ceramic material and are mounted loosely in said journal means of said structures.

3. In a kiln as recited in claim 1, in which said elongated firing oven includes a top portion of fire brick construction, a metallic supporting structure having a part thereof below said top fire brick portion and movably connected thereto, a lower fire brick portion defining in part the lower part of the oven, and said part of said metal supporting structure being mounted above said lower fire brick portion, and means for insulating said metallic structure from said oven and from said upper and lower fire brick portions.

6 4. In a kiln as recited in claim 1, in which a metallic interponent structure is disposed between a top fire brick portion and a lower fire brick portion and comprises an upper metallic support for said upper fire brick portion a lower metallic mounting for supporting on said lower fire brick portion and vertical metal connectors extending between said metal portions and being free to flex in a direction longitudinally of said kiln.

5. In a kiln as recited in claim 4, in which a resilient insulating means is disposed between said metallic structure between said top fire brick portion and said lower fire brick portion.

6. In -a kiln as recited in claim 1, in which a metallic interponent structure is disposed between a top fire brick portion and lower fire brick portion and includes a metallic support for said upper brick portion, and means for hanging a row of fire brick below said metallic support and spaced above said lower fire brick portion, and ceramic insulating means disposed both above and below said row of hanging fire brick.

7. In a kiln as recited in claim 1, which includes a series of heating means disposed along said oven for directing heat thereto, said series of heating means being divided into two groups, means for supplying the first group of heating means at said entrance end with a greater amount of heat units than the remaining portion of said heating means to assist in raising the temperature of said articles to the desired temperature.

References Cited by the Examiner UNITED STATES PATENTS 823,226 6/1906 Ridd 2'636 1,729,164 4/ 1929 Fergren. 1,938,581 12/1933 Cope et a1 25-142 2,205,242 6/ 1940 Davis et a1. 2636 WILLIAM J. STEPHENSON, Primary Examiner. 

1. IN A KILN FOR RAPID FIRING A SINGLE LAYER OF CERAMIC ARTICLES SUCH AS GLAZED CERAMIC TILE, AN ELONGATED FIRING OVEN COMPRISING AN UPPER FIRE BRICK CONSTRUCTION AND A LOWER FIRE BRICK CONSTRUCTION, MEANS SEPRATING SAID UPPER AND LOWER FIRE BRICK CONSTRUCTIONS INCLUDING A PAIR OF JOURNALING STRUCTURES EXTENDING ALONG EACH SIDE OF SAID OVEN, SAID STRUCTURES BEING FORMED OF A MATERIAL HAVING A DIFFERENT HEAT EXPANSION CHARACTERISTIC THAN FIRE BRICK, HEAT INSULATING MEANS FOR PROTECTING EACH OF SAID JOURNALING STRUCTURES FROM THE HEAT OF THE OVEN, A SERIES OF JOURNAL MEANS IN EACH OF SAID JOURNALING STRUCTRES, A SERIES OF PARALLEL HORIZONTAL ROLLERS JOURNALED IN SAID JOURNAL MEANS OF SAID STRUCTURES, AND EXTENDING THROUGH SAID OVEN AND SAID INSULATING MEANS, SAID ROLLERS BEING IN AN INTERMEDIATE POSITION IN SAID OVEN TO PROVIDE A PORTION OF SAID OVEN ABOVE SAID ROLLERS AND A PORTON OF SAID OVEN BELOW SAID ROLLERS FOR DIRECT HEATING OF A CERAMIC ARTICLE SUPPORTED ON THE ROLLERS AND CONVEYED THEREBY THROUGH THE OVEN, AND MEANS FOR DRIVING SAID ROLLERS TO CONVEY THE CERMIC ARTICLES THROUGH THE OVEN. 